Improvement in the manufacture of pig-iron



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Letters Patent No. 94,471, dated September 7, 1869.

IMPROVEMENT IN THE MANUFACTURE OF PIG-IRON.

The Schedule referred to in these Letters Patent and making part of the same.

To whom it may concern Be it known that I, JOHN BURT, of Detroit, county of \Vayne, and State of Michigan, have invented certain new and useful Improvements in Pig-Iron; and I hereby declare the following to be a full, clear, and exact description of the same, reference being bad to the accompanying drawings.

.My invention relates to the treatment of the molten metal, which is run from the blast or reducing-furnace into moulds or pig-beds, so called and Its object is-- V First, to improveaud render more uniform the quality of the pig,'whatevermay be the purpose for which it is designed, Whether for foundry-steel or malleable iron.

Second, to facilitate the casting of the pigs, so that they maybe manufactured in a simpler, better, and more economical manner than has heretofore been practicable.

To accomplish the first object I have in view, my invention consists in incorporating carbonizing or oxidizing-agonts with the metalat the time it is being formed into pig, by lining or spreading over the bottom or bottom and side of the pig-bed with either carbon or oxides, or with a mixture of both, according to the kind of metal to be produced, which, when the molten metal is tapped olf fromthe furnace, and run into the moulds, will permeate the mass of metal of which each pig composed, and become incorporated with it. For instance, if it be desired to bring the molten metal to a more highly carbonaceous condition, I line or spread over the bottom of the moulds, or the bottom and sides of the moulds, with powdered animal or vegetable-cliarcoal, which maybe tamped or mixed with petroleum; or I can employ any other ia-rbonizing-agent with good results, such, for instance, as a wash of carbonate of lime applied to the inner surface of the moulds.

In case the pig is to be used for the manufacture of malleable iron, I place, in the pig-bed, oxides, either dry or moistened, and made into a plastic mass; or, if. the nature of the metal or kind of pig. to be produced requires it, 1 place in the moulds a mixture of oxides and carbon in suitable proportions.

In order to the advantageous use of my invention, the pig-bed should be made of metal or fire-clay, or othenrefractory substance, made in the required form, to which bed the oxidizing or cru'hzmizlrig-agents are applied as above describerh The advantages attending this method of making the pig are many. Among those especially noticeable may be mentioned the following:

First, the carbonizing and other agents, as above specified, by reason of their less specificgravity, rise up into and permeate, and become incorporated with the cast-metal .at the same-time, as the metal soon chills, the carbons and oxides do not gather at the top, but are held in the'mass of metal, which is of a more homogeneous quality than is ordinarily found.

Second, the oxidation at the surface of the pig, resulting from its contact with the atmosphere, and the consequent formation of scale, are prevented. The carbons serve to neutralize the oxidizing influence of the atmosphere, and the oxides, when en'iployed, serve as agents to incorporate all that would otherwise be scale -with the body of the pig; and, moreover, no sand can adhere to the pig, so that its quality is thus improved at the same time that a saving of metal is effected.

Third, the method described effectually prevent-s all danger of the boiling of the metal, the injurious ciiects of which are well known to all manufacturers of iron. The second portion of my invention is partly designed to give full effect to the first part of my invention as above set forth, but it may be used also in the manufacture of ordinary pig-iron. It consists of certain arrangements of the pig-bed or moulds, which can best be explained by reference to the acconmauying drawings, in which Figure 1 is a top view of a pig-bed made in accordance with my inventimi.

Figure 2 is a transverse sect-ion of the same, showing a modified arrangement of the trough from which the metal passes to the pig-moulds.

Figures 3 and4 represent modified arrangements of the pig-moulds, the first showing the moulds arranged vertically, and the second showing the same placed in an inclined position.

The main object I have here in view is to cast each pig so that it shall be entirely distinct and separate from the others, thus doing, away with the necessity which ordinarily arises for the formation of the sow; so'called, and allowing the pigs to be perfectly formed without the ragged and broken ends which are pro duced when they are cast in the ordinary way, and then broken off from the sow.

To this end, I make each pig-mould a distinct and separate, and so that it shall have nocmnmunication with the others, directly or indirectly, as shown in. the various figures of the drawing.

Over the had thus made, 1 place a trough, I), which straddles or is supported in an elevated position above the bed, and has formed in it a series of apertures, 0, each one of which leads into a COI'I'GSPl'llllllllg mould in the bed below. This trough is located at any conven' ient point over'the bed, or it'may be placed at one side of the same, each of its holes -c communicating with its corresponding mould in any suitable manner.

The molten metal, when tapped off from the blastfurnacc, is run into the trough b by any ordinary or suitable means, and thence it passes through the holes 0 into the moulds, which are filled, while at the same time they have no communication with one another, and perfectly-formed pigs are thus produced.

The trough bfmay be fixed or stationary, as shown in fig. 1, or it may be mounted on rollers or trucks, as shown in fig. 2,. which run, on ways or'tracks passing along each side of the bed, so. that the trough may be brought over any part-of the bed, or-removed entirely out of the way, as circumstances require,

The pig-bed, underv this part of my invention, may

be formedof the usual materials, the trough being, of

course, metal, or'some refractory substance; but when the bed is to be lined with carbonizing or other agents, as hereinbefore specified, it should be also of metal, fireclay, or like material.

It may also be found advantageous to pass water, either hot or cold, or other suitable liquid, through the moulds, for the purpose of cooling the iron more or less rapidly, as required for the purpose for which it is designed, and at the same time of preserving the moulds, by contact of water, from burning. .This can be ac complishedby means of pipes inserted in or passing through the moulds, as represented by the dotted lines at d, fig. 1, wherethe pipes are represented as passing through the partition-walls of the bed. .By such means the advantages specified can readily be realized. I

The pipes may be of any number or size required, so that when occasion demands, the moulds may be surrounded either wholly or partly by a water-jacket.

The supply of the water can be produced by anyof the usual means employed for such purposes.

In order to economize room, as well as for the purposes to be presently specified, I prefer to arrange the moulds vertically, as shown infig. 3, or in an inclined position, as seen in fig. 4; They are arranged and held in either position in any suitable manner, but I prefer, in the first instance, to arrange the" moulds, touching each other, in two or more rows, whichare placed in a trench of suitable depth, over whichthe trough b is located. The most desirable method of constructing the moulds is to make each in two-parts, which, when put together, will have a rectangular form. mould may be clamped together separately, but inpractice this will not be found necessary, for by placing them, one against the other, in the trench, the exterior mould only being fastened or upheld by suitable fiistening-devices, and then packing them with fire-brick, or other suitable materials, they will be held securely in place. This method affords an advantage in this, that after/the pigs have been moulded, they can be readily removed by beginning at one end of the trench, and opening the moulds, one after the other, so as to obtain access .to the pigs, which can then be readily lifted out.

In arranging the two rows of moulds inan inclined position, with their open upper ends converging, as-

shown in fi 4, a mould of suitable shape should be built, upon which the divided moulds are laid, they being held in this position by means which will readily suggest themselves to iron-workers or m'anufactutefil The moulds, whether vertical or inclined, are made of metal or refractory material, and are filled from the trough b, as hereinbefore explained. In order to fill thetwo parallel rows of moulds, there may be either Each two series of holes in the trough, or, if it have but one series, it can be moved over the next set of moulds after filling the first set.

I find the use of moulds, placed as shown in figs. 3 and 4, to be very advantageous in carrying out the first part of my invention. The carbonizing or oxidizingagents, or whatever mixtures of ingredients are employed, are put in the bottom of the moulds, and as the metal drops from its elevated position in the trough, the whole mass is thoroughly agitated, thus effecting a very'intimate mixture of all the substances in the moulds, and making a greatly-improved quality of pigiron.

In order to prevent the too rapid rising of the carbons, oxides, or other agents, I can place upon them, before running in the metal, scraps, shavings, or borings of cast-iron, which serve to hold said agents down,

and to prevent their flying, and at the same time improve the pig-metal. As the molten mass runs'in, the metal scraps or borings gradually melt, and become fused, and the oxides or carbon, or both, are released,

and rise through and permeate the body of the pi". This portion of my invention is equally applicable to horizontal moulds, which are first washed or lined with the carbonizing or oxidizing-agent, after which I spread over the bottom the proper quantity of scrap cast-metal or borings, which, when the molten metal'is runin, become fused and il'lcorporated with the pig, and serve to increase the quantity of the iron.

The pig can also be brought to condition to be used to advantage in the manufacture of malleable iron, by substituting for the cast-iron scrap, 860., above specified, wrought-metal scrap, borings, or turnings.

In the manufacture of pig-iron,

I claim-- 1. The method of lining or spreadingover the pigbed or mould with oxidizing or carbonizing-ageuts, or a mixture of both, substantially as and for the purposes set forth.

2. The employment, with a series of non-communicating pig-moulds, of a trough, whether movable or not, arranged to communicate with and conduct the molten metal to each mould separately, substantially as and for the purposes set forth.

3. The arrangement of the pig-moulds in a vertical or inclined position, the same being filled by-means of the trough, which is located above, and communicates with them, substantially as and for the purposes set forth.

4. The mixture, with the molterrmetal, of cast or wrought-iron scrap, borings, or turnings, placed in or spread over the bottom of the mould, substantially as and for the purposes described.

5. The mode of cooling the iron and preventing the moulds from burning, bypassing water or other suitable liquid through one or more pipes inserted in orlextending through the pig-bed or moulds, from end to end, or by surrounding the moulds wholly or partly with'water,

substantially as herein set forth.

I In testimonywliereof, I have signed my name to this specification, befin'e two subscribing witnesses.

JOHN BURT.

\Vitnesses M. BAILEY, Eon. F. Baowx. 

